Disposable hazardous and radioactive liquid hydrocarbon waste composition and method

ABSTRACT

An improved method of disposing of radioactive or hazardous liquid hydrocarbon compositions comprises placing the liquid hydrocarbons in a container and adding an organic ammonium montmorillonite in ratios of between about 1:2 and 3:1, by volume, respectively. The organic ammonium montmorillonite has at least 10 carbon atoms. A polar organic compound having between 1 and about 10 carbon atoms is also preferably added with the montmorillonite. Where the liquid waste material includes 5% or more of water in addition to the liquid hydrocarbon a minus 200 mesh sodium montmorillonite is also preferably added.

This is a continuation of co-pending application Ser. No. 06/818,323,filed on Jan. 13, 1986 (abandoned).

BACKGROUND OF THE INVENTION

The disposal of hazardous and radioactive waste materials is of extremeimportance. Federal and state laws and requirements covering suchdisposals are particularly severe and stringent due to the dangers toplant and animal life if the desired standards are not met and thehazardous or radioactive materials become exposed to the environment.Because of the potential dangers, the United States Nuclear RegulatoryCommission has not only identified the hazardous and radioactivematerials to date, which list is continually being amended and updated,but has set forth specific standards and requirements for protecting theenvironment against such waste materials. The resulting laws andregulations are set forth in 10 CFR, particularly sections 1-199. Otherregulations relating to transportation, packaging, labeling andidentifying hazardous and radioactive materials are also found in 40 CFR1-799 and 49 CFR 100-177. Other publications which relate toclassifying, indexing and discussing radioactive and hazardous wastematerials include DOE/LLW-14T publication "Waste Classification, AProposed Methodology For Classifying Low-Level Radioactive Waste", Dec.1982, DOE/LLW-17T, "Survey of Chemical And Radiological IndexesEvaluating Toxicity" , March 1983, FW-874, "Hazardous Waste LandTreatment", April 1983 and FW-872 "Guide To The Disposal Of ChemicallyStabilized and Solidified Waste", September 1982.

It is the common practice to process liquid hazardous or radioactivematerials by adding absorbents in an attempt to enhance handling andtransportation, as well as eventual storage thereof. The materials thathave been used heretofore include diatomaceous earth, vermiculite orexpanded mica such as zonolite and krolite, portland and gypsum cements,as well as clay materials such as calcium bentonites. A problem withsuch materials is that only a relatively small amount of liquid can beabsorbed or otherwise treated with less than satisfactory results. Forexample, liquid materials are desirably transported and disposed of in55 gallon drums. However, it has been found with the use of theseabsorbents, solid compositions cannot be achieved or if temporarilyachieved, liquid separation occurs during transportation or storage. Anyseparated or free-standing liquids are especially undesirable because ofthe potential danger of leakage from a ruptured or opened container. Itis to the substantial elimination of such problems that the presentinvention is directed.

SUMMARY OF THE INVENTION

An improved method of treating hazardous and radioactive organic orhydrocarbon waste compositions comprises placing the materials in acontainer, such a 55 gallon drum, and adding an organic ammoniummontmorillonite with stirring until the mixture has substantiallysolidified. It is also desirable to add a small amount of polar organicsolvent with the organic ammonium montmorillonite to speed up thesolidification process. Where over about 5%, by volume, of waste liquidcomposition is water, it is also desirable to add sodium montmorillonitewith the organic ammonium montmorillonite in amounts directlyproportional to the amount of water present in the waste. The resultingsubstantially solidified waste material may be handled, transported andstored under a variety of conditions for extended periods of timewithout evidence of liquid separation or deterioration. These and otheradvantages as well as the specific materials used in the invention willbe more particularly described in the following detailed description.

DETAILED DESCRIPTION OF THE INVENTION

The method of solidifying the hazardous and radioactive liquid wastecompositions according to the invention applies to a great variety ofsuch materials. For example, in the radioactive waste disposal field,liquids which must be treated and disposed of include reactor plantorganic liquids such as turbine, cutting and lubricating oils, solventsludges which are used to degrease the reactor components such as FreonTF, cleaning solvents such as Stoddard solvents, decontaminationsolvents, and aqueous mixtures of the above-noted organic materials,particularly those containing between from 5 to about 75% hydrocarbonsand even up to 100% hydrocarbons. In addition, a great quantity of suchwastes are aqueous liquids, containing over about 95% water contaminatedwith radioactive materials such as greases from reactor plant turbines.Hospital-sourced contaminated liquids contain radioactive materials usedin cancer treatments. From such sources, particularly common materialsinclude the radioactive cobalts such as cobalt 57, cobalt 58 and cobalt60, cesium, plutonium and uranium isotopes, and the like. However, it isto be understood, according to the invention, that any radioactivematerials that are to be disposed of and are defined in the aforesaidlaws, regulations, and documents are intended to be included in thecompositions treated according to the method of this invention, as wellas any later identified and added radioactive materials, regardless ofsource and regardless of the specific radioactive material orradioisotope.

Common hazardous waste materials include acids, bases, chlorinatedhydrocarbons including PCB, dioxins, and the like. Again, these as wellas the radioactive materials may be in aqueous liquids, containing up tosubstantial amounts of hydrocarbons. Moreover, as used herein,"hydrocarbons" is intended to define any such oils, solvents and otherorganic or non-aqueous liquids as generally described above which havebeen contaminated with radioactive materials or which themselves areconsidered hazardous chemicals according to governmental regulations.

The primary material used in the method of the present invention fortreating and substantially solidifying liquid organic or hydrocarboncontaining hazardous and radioactive waste materials is an organicammonium montmorillonite composition consisting of sodiummontmorillonite and a salt of an amine or a quaternary ammonium salthaving at least 10 carbon atoms in the organic portion of the molecule.The montmorillonite may be a calcium, magnesium or sodiummontmorillonite, or mixtures of two or more of these montmorillonites,or may be another water swelling mineral with significant ion exchangecapacity such as Saponite, Hectorite, Beidellite, Nontronite, Stevensiteand Sauconite. Although for some uses the montmorillonite or othermineral may be combined directly with the amine salt to produce theorganic ammonium montmorillonite, where sodium is not the majorexchangeable cation, it is preferred to exchange sodium for the calciumor magnesium. This may be readily accomplished by mixing the mineralwith an aqueous solution of a sodium salt such as sodium carbonate orsodium chloride and recovering the high sodium content product. Apreferred material is a sodium montmorillonite having preferably over50% milliequivalent exchangeable cation concentration, more preferablybetween about 60 and about 75% sodium meq/% in which the sodium has beenexchanged for an organic ammonium component through ion exchangereactions. A most preferred sodium montmorillonite is disclosed inco-pending application Ser. No. 743,057 filed Jun. 10, 1985, thedescription thereof being incorporated herein by reference.

The above-described minerals, their high sodium ion-exchange products,or sodium montmorillonite are reacted with a primary, secondary ortertiary amine, amine salt, or a quaternary ammonium salt. Suitablecompounds within this definition are those disclosed and prepared byreactions described in U.S. Pat. Nos. 2,531,427 and 2,966,506, therelevant portions thereof being incorporated herein by reference.Preferred amines used are those containing at least 10 carbon atoms suchas dodecyl, hexadecyl, octadecyl, dimethyloctadecyl, and the like.However, the amines may be aliphatic, aromatic, cyclic, heterocyclic, orpolyamines, A readily available and useful material is dimethyldihydrogenated tallow ammonium montmorillonite. The aforesaidmontmorillonite, minerals, or sodium montmorillonite may be reacted withthe amine or ammonium salts by mixing or mulling the dry base materialwith the selected amine. Alternatively, a wet process may be usedwherein the base mineral is slurried in fresh water and the amine orammonium salt is added and properly mixed. The reaction product isfiltered or centrifuged and then dried to a low moisture content. Asmall but important and significant percentage of water is retained toattain maximum product efficiency. Usually a few percent of water, saybetween about 1 and about 5% water based on the final organic ammoniummontmorillonite is preferred. The resulting organic ammoniummontmorillonites are highly organophyllic and thus useful in the processof the invention for substantially solidifying the waste liquidhydrocarbon materials.

In solidifying (substantially solidifying) substantially 100%hydrocarbon radioactive or hazardous waste liquids, the organic ammoniummontmorillonite may be used alone, although preferably a polar organiccompound will also be added as will be explained hereinafter. The amountof montmorillonite used in the process will achieve a liquidhydrocarbon:montmorillonite ratio of between about 1:2 and 3:1, by bulkvolume, respectively. The liquid hydrocarbon is placed normally in avessel or container, commonly a 55 gallon drum, and the montmorilloniteis added slowly over a period of at least a few minutes with continuedstirring until the composition becomes solidified. By the term"solidified" or "substantially solidified" herein it is intended todefine a material which is not pourable.

The solidification process is enhanced by additionally adding a polarorganic compound with the organic ammonium montmorillonite as it isstirred and blended with the liquid waste material. The addition of thepolar organic compound provides for substantial reduction in the amountof organic ammonium montmorillonite required to achieve the samesubstantial solidification of liquid. It has been found that for somehydrocarbon wastes, the amount of organic ammonium montmorilloniteneeded for solidification is reduced by 50% or more. Suitable polarorganic compounds include alcohols, carbonates, acetates, ethers,ketones, benzoates and halogenated hydrocarbons having between about 1and about 10 carbon atoms. Within these groups samples of suitablematerials include diethyl carbonate, propylene carbonate, methylacetate,ethylacetate, isoamylacetate, diisopropyl ether, diethyl ether,methylethyl ketone, diethyl ketone, diisopropyl ketone, ethyl benzoate,trichloroethane, carbon tetrachloride, and chlorobenzene. Most preferredare the lower molecular weight alcohols having between 1 and about 8carbon atoms, particularly methyl alcohol, ethyl alcohol, n-propylalcohol, isopropyl alcohol, tert-butyl alcohol, etc. These examples areintended only to indicate a number of useful polar organic solvents orcompounds and the list is not intended to be exhaustive. The amount ofpolar organic compound will be between about 1 and about 10% of thevolume of liquid hydrocarbon, preferably around 5%. The addition of thepolar organic compound is particularly desirable where the hydrocarbonliquid is above about 70% volume of the waste liquid being treated.

Where the liquid hydrocarbon waste composition contains substantialamounts of water, i.e., between 5 and 95% by volume of the wastematerial to be treated, it is also desirable according to the inventionto include a finely divided sodium montmorillonite in which at least amajor portion and up to substantially all of the particles are about 200mesh or smaller. A preferred sodium montmorillonite is described in U.S.application Ser. No. 743,057, filed Jun. 10, 1985 and incorporated byreference herein. Accordingly, the preferred sodium montmorillonite usedhas over about 50% milliequivalent exchangeable cation concentration andmore preferably above about 60%. Even more preferred materials are thosehaving a cation exchange capacity up to even 95-100 meq/% with nominalranges of the preferred material being between about 75 and about 80meq/%. When treating waste materials containing between 5 and 95% watermixed with hydrocarbon liquid, the organic ammonium montmorillonite andsodium montmorillonite mixture is used at the rate of between about 2.3and about 4.6 pounds of mixture per gallon of liquid waste. Moreover,the amount of sodium montmorillonite used is such as to give a ratio oforganic ammonium montmorillonite:sodium montmorillonite that is aboutdirectly proportional to the ratio of liquid hydrocarbon:water, byvolume, respectively. Otherwise, the materials added in the same way aspreviously described with the organic and sodium montmorillonites beingadded separately or together to the liquid waste material to besolidified while stirring until substantial solidification is achieved.

In treating hazardous or radioactive liquid hydrocarbon-water mixturesin which the hydrocarbon is present above about 70% and up to about 95%,it is further preferred to additionally add a polar organic compound aspreviously described to the organic ammonium montmorillonite and sodiummontmorillonite treating mixture. The amount of polar organic compoundadded will also be as previously described, i.e., between 1 and about10% based on the volume of liquid hydrocarbon being treated. Again, theuse of the polar organic activator substantially reduces the amounts oforganic ammonium montmorillonite required to obtain suitable hydrocarbonliquid solidification.

In treating the waste liquid compositions to obtain solidification, aspreviously noted, the waste material is placed in a 55 gallon drum andthe montmorillonite is added with stirring until substantialsolidification is achieved. Where mixtures of organic ammoniummontmorillonite and sodium montmorillonite are used, thesemontmorillonites may be mixed and added at one time with stirring orthey may be added separately. Where activator is used, it is preferredto stir in the organic ammonium montmorillonite or the mixture thereofwith sodium montmorillonite first and thereafter add the polar organiccompound which is then mixed well. If additional solidification isneeded after the initial amounts of the aforesaid montmorillonites andpolar organic compound have been mixed with the waste material,additional mixture of the aforesaid montmorillonites and polar organiccompound may be added at a convenient ratio of 1 gallon of the polarorganic compound per 100 pounds of the organic ammonium montmorillonitepresent in the mixture. The composition should again be stirred and thedrum then sealed for 24 hours and thereafter inspected. If any freeliquid is standing or has risen to the top of the composition,additional montmorillonite mixture and polar organic compound in thesame proportions as above described should be added with stirring tocomplete the solidification process.

By way of examples different liquid hydrocarbon hazardous wastematerials were treated as follows:

EXAMPLE I

Forty-five gallons of a hazardous mixture of waste lubricating andcutting oil were placed in a 55 gallon drum. To the liquid hydrocarbonwaste mixture was added 185 pounds of dimethyl dihyrogenated tallowammonium montmorillonite with stirring. The resulting mixture became setup within 24 hours to a thick unpourable composition.

EXAMPLE II

Another 45 gallon sample of the hydrocarbon waste mixture of Example Iwas treated by adding 130 pounds of the same organic ammoniummontmorillonite and 2.7 gallons of methyl alcohol. The mixture wasstirred for about 5 minutes during which time it set up to a thick,stiff, unpourable composition.

EXAMPLE III

A 45 gallon mixture of 50% hydrocarbon waste of Example I and 50% waterwere treated by adding a mixture of 50 pounds of the same organicammonium montmorillonite and 50 pounds of sodium montmorillonite (minus200 mesh) with stirring. After 24 hours the composition was a thick butflowable liquid. To this mixture was added 1 gallon of methyl alcoholwith stirring. After about 15 minutes the mixture had set up to become avery stiff and unpourable composition.

EXAMPLE IV

To a sample of the same hydrocarbon, water mixture of Example III wasadded a mixture of 80 pounds of the Example I organic ammoniummontmorillonite and 80 pounds sodium montmorillonite (minus 200 mesh)with stirring for about 15 minutes to achieve the same Example IIIconsistency.

I claim:
 1. A method of treating a radioactive or hazardous wastematerial consisting essentially of liquid hydrocarbon compositioncomprising placing said radioactive or hazardous liquid hydrocarboncomposition in a container and mixing therewith an organic ammoniummontmorillonite, said liquid hydrocarbon:organic ammoniummontmorillonite ratio being between about 1:2 and 3:1, by volume,respectively, said organic ammonium montmorillonite having at least 10carbon atoms therein, and between about 1 and about 10% by volume ofsaid liquid hydrocarbon composition a low molecular weight aliphaticalcohol having from 1 to 8 carbon atoms until the composition comprisesan unpourable, free standing solid.
 2. The method of claim 1 whereinsaid organic ammonium montmorillonite comprises a quaternary ammoniummontmorillonite.
 3. A solidified hazardous or radioactive liquidhydrocarbon composition consisting essentially of said liquidhydrocarbon, an organic ammonium montmorillonite having at least 10carbon atoms, and a low molecular weight aliphatic alcohol having from 1to 8 carbon atoms, the ratio of said liquid hydrocarbon and said organicammonium montmorillonite being between about 1:2 and about 3:1, byvolume, respectively, and said alcohol being between about 1 and about10% by volume of said liquid hydrocarbon and wherein said compositioncomprises an unpourable, free standing solid.
 4. A method of disposingof a hazardous or radioactive liquid composition consisting essentiallyof between about 5 and about 95% liquid hydrocarbon .[.nd.]. .Iadd.and.Iaddend.between about 95 and about 5% water, by volume, respectively,comprising placing said liquid in a container, adding between about 2.3and about 4.6 pounds of a mixture of an organic ammonium montmorilloniteand sodium montmorillonite of at least 50% minus 200 mesh particle sizeper gallon of said liquid composition wherein the ratio of said organicammonium montmorillonite: sodium montmorillonite is about directlyproportional to the ratio of liquid hydrocarbon:water, by volume,respectively, and between 1 and about 10% aliphatic alcohol havingbetween 1 and 8 carbon atoms based on the volume of said liquidhydrocarbon, while stirring to achieve an unpourable, free standingsolid.
 5. A solidified hazardous or radioactive liquid compositionconsisting essentially of a waste portion of between about 5 and about95% liquid hydrocarbon and between about 95 and about 5% water, byvolume, respectively, between about 2.3 and about 4.6 pounds of amixture of an organic ammonium montmorillonite and sodiummontmorillonite having a nominal particle size of minus 200 mesh pergallon of said waste portion, the ratio of organic ammoniummontmorillonite:sodium montmorillonite being about directly proportionalto the ratio of liquid hydrocarbon:water, by volume, respectively, andbetween 1 and about 10% aliphatic alcohol having between 1 and 8 carbonatoms based on the volume of said liquid hydrocarbon and wherein saidcomposition comprises an unpourable, free standing solid.
 6. Thecomposition of claim 5 wherein said organic ammonium montmorillonite hasat least 10 carbon atoms.
 7. A method of treating a radioactive orhazardous waste material consisting essentially of liquid hydrocarboncomprising placing said radioactive or hazardous liquid hydrocarboncomposition in a container and mixing therewith an organic ammoniummontmorillonite, said liquid hydrocarbon:organic ammoniummontmorillonite ratio being between about 1:2 and 3:1, by volume,respectively, said organic ammonium montmorillonite having at least 10carbon atoms therein, and between about 1 and about 10% by volume ofsaid liquid hydrocarbon composition a low molecular weight polar organiccompound having between 1 and about 10 carbon atoms selected from thegroup consisting of aliphatic ketones, aliphatic acetates and aliphaticalcohols until the composition is substantially solid.
 8. The method ofclaim 7 wherein said polar organic compound is selected from the groupconsisting of isopropyl alcohol, hexyl alcohol, ethyl acetate and methylethyl ketone. .Iadd.
 9. A method of treating a radioactive or hazardouswaste material consisting essentially of liquid hydrocarbon compositioncomprising mixing therewith an organic ammonium montmorillonite, saidliquid hydrocarbon:organic ammonium montmorillonite ratio being betweenabout 1:2 and 3:1, by volume, respectively, said organic ammoniummontmorillonite having at least 10 carbon atoms therein, and betweenabout 1 and about 10% by volume of said liquid hydrocarbon composition alow molecular weight aliphatic alcohol having from 1 to 8 carbon atomsuntil the composition comprises a free standing solid. .Iaddend..Iadd.10. A method of disposing of a hazardous or radioactive liquidcomposition consisting essentially of between about 5 and about 95%liquid hydrocarbon and between about 95 and about 5% water, by volume,respectively, comprising adding between about 2.3 and about 4.6 poundsof a mixture of an organic ammonium montmorillonite and sodiummontmorillonite of at least 50% minus 200 mesh particle size per gallonof said liquid composition wherein the ratio of said organic ammoniummontmorillonite:sodium montmorillonite is about directly proportional tothe ratio of liquid hydrocarbon:water, by volume, respectively, andbetween 1 and about 10% aliphatic alcohol having between 1 and 8 carbonatoms based on the volume of said liquid hydrocarbon, while stirring toachieve a free standing solid. .Iaddend. .Iadd.11. A method of treatinga radioactive or hazardous waste material consisting essentially ofliquid hydrocarbon comprising mixing therewith an organic ammoniummontmorillonite, said liquid hydrocarbon:organic ammoniummontmorillonite ratio being between about 1:2 and 3:1, by volume,respectively, said organic ammonium montmorillonite having at least 10carbon atoms therein, and between about 1 and about 10% by volume ofsaid liquid hydrocarbon composition a low molecular weight polar organiccompound having between 1 and about 10 carbon atoms selected from thegroup consisting of aliphatic ketones, aliphatic acetates and aliphaticalcohols until the composition is substantially solid. .Iaddend.